Revert "[SCCP] Use SimplifyBinOp for non-integer constant/expressions & overdef."

This reverts commit 1a02aaeaa4. Crashes on
the following test case:

$ cat crash.ll
source_filename = "__compute_module"
target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
target triple = "x86_64-grtev4-linux-gnu"

@0 = private unnamed_addr constant [24 x i8] c"\00\00\C0\7F\00\00\C0\7F\09\85\08?\ED\C94\FE~\EB/\F3\90\CF\BA\C1"
@1 = private unnamed_addr constant [24 x i8] c"\00\00\C0\7F\A3\A0\0FA\00\00\C0\7F\00\00\C0\7F\00\00\00\00\02\9AA\00"

define void @IgammaSpecialValues.448() {
entry:
  br label %fusion.26.loop_header.dim.0

fusion.26.loop_header.dim.0:                      ; preds = %fusion.26.loop_header.dim.0, %entry
  %fusion.26.invar_address.dim.0.0 = phi i64 [ 0, %entry ], [ %invar.inc17, %fusion.26.loop_header.dim.0 ]
  %0 = getelementptr inbounds [6 x float], [6 x float]* bitcast ([24 x i8]* @0 to [6 x float]*), i64 0, i64 %fusion.26.invar_address.dim.0.0
  %1 = load float, float* %0
  %2 = fmul float %1, 0.000000e+00
  %3 = getelementptr inbounds [6 x float], [6 x float]* bitcast ([24 x i8]* @1 to [6 x float]*), i64 0, i64 %fusion.26.invar_address.dim.0.0
  %4 = load float, float* %3
  %5 = fneg float %4
  %6 = fadd float %2, %5
  %invar.inc17 = add nuw nsw i64 %fusion.26.invar_address.dim.0.0, 1
  br label %fusion.26.loop_header.dim.0
}

$ opt -ipsccp -S < crash.ll
opt: llvm/include/llvm/Analysis/ValueLattice.h:251: bool llvm::ValueLatticeElement::markConstant(llvm::Constant *, bool): Assertion `getConstant() == V && "Marking constant with different value"' failed.
This commit is contained in:
Benjamin Kramer 2020-04-13 11:23:26 +02:00
parent 2e8188ff48
commit 06408451bf
3 changed files with 30 additions and 29 deletions

View File

@ -28,7 +28,6 @@
#include "llvm/ADT/Statistic.h"
#include "llvm/Analysis/ConstantFolding.h"
#include "llvm/Analysis/GlobalsModRef.h"
#include "llvm/Analysis/InstructionSimplify.h"
#include "llvm/Analysis/TargetLibraryInfo.h"
#include "llvm/Analysis/ValueLattice.h"
#include "llvm/Analysis/ValueLatticeUtils.h"
@ -370,10 +369,8 @@ private:
// markConstant - Make a value be marked as "constant". If the value
// is not already a constant, add it to the instruction work list so that
// the users of the instruction are updated later.
bool markConstant(ValueLatticeElement &IV, Value *V, Constant *C,
bool MayIncludeUndef = false) {
if (!IV.markConstant(C, MayIncludeUndef))
return false;
bool markConstant(ValueLatticeElement &IV, Value *V, Constant *C) {
if (!IV.markConstant(C)) return false;
LLVM_DEBUG(dbgs() << "markConstant: " << *C << ": " << *V << '\n');
pushToWorkList(IV, V);
return true;
@ -957,28 +954,23 @@ void SCCPSolver::visitBinaryOperator(Instruction &I) {
if (V1State.isOverdefined() && V2State.isOverdefined())
return (void)markOverdefined(&I);
// If either of the operands is a constant, try to fold it to a constant.
// Both operands are non-integer constants or constant expressions.
// TODO: Use information from notconstant better.
if ((V1State.isConstant() || V2State.isConstant())) {
Value *V1 = isConstant(V1State) ? getConstant(V1State) : I.getOperand(0);
Value *V2 = isConstant(V2State) ? getConstant(V2State) : I.getOperand(1);
Value *R = SimplifyBinOp(I.getOpcode(), V1, V2, SimplifyQuery(DL));
auto *C = dyn_cast_or_null<Constant>(R);
if (C) {
// X op Y -> undef.
if (isa<UndefValue>(C))
return;
// Conservatively assume that the result may be based on operands that may
// be undef.
return (void)markConstant(IV, &I, C, /*MayIncludeUndef=*/true);
}
if (isConstant(V1State) && isConstant(V2State)) {
Constant *C = ConstantExpr::get(I.getOpcode(), getConstant(V1State),
getConstant(V2State));
// X op Y -> undef.
if (isa<UndefValue>(C))
return;
return (void)markConstant(IV, &I, C);
}
// Only use ranges for binary operators on integers.
if (!I.getType()->isIntegerTy())
return markOverdefined(&I);
// Try to simplify to a constant range.
// Operands are either constant ranges, notconstant, overdefined or one of the
// operands is a constant.
ConstantRange A = ConstantRange::getFull(I.getType()->getScalarSizeInBits());
ConstantRange B = ConstantRange::getFull(I.getType()->getScalarSizeInBits());
if (V1State.isConstantRange())

View File

@ -3,8 +3,10 @@
define void @shift_undef_64(i64* %p) {
; CHECK-LABEL: @shift_undef_64(
; CHECK-NEXT: store i64 0, i64* [[P:%.*]]
; CHECK-NEXT: store i64 -1, i64* [[P]]
; CHECK-NEXT: [[R1:%.*]] = lshr i64 -1, 4294967296
; CHECK-NEXT: store i64 [[R1]], i64* [[P:%.*]]
; CHECK-NEXT: [[R2:%.*]] = ashr i64 -1, 4294967297
; CHECK-NEXT: store i64 [[R2]], i64* [[P]]
; CHECK-NEXT: [[R3:%.*]] = shl i64 -1, 4294967298
; CHECK-NEXT: store i64 [[R3]], i64* [[P]]
; CHECK-NEXT: ret void
@ -23,8 +25,10 @@ define void @shift_undef_64(i64* %p) {
define void @shift_undef_65(i65* %p) {
; CHECK-LABEL: @shift_undef_65(
; CHECK-NEXT: store i65 0, i65* [[P:%.*]]
; CHECK-NEXT: store i65 0, i65* [[P]]
; CHECK-NEXT: [[R1:%.*]] = lshr i65 2, -18446744073709551615
; CHECK-NEXT: store i65 [[R1]], i65* [[P:%.*]]
; CHECK-NEXT: [[R2:%.*]] = ashr i65 4, -18446744073709551615
; CHECK-NEXT: store i65 [[R2]], i65* [[P]]
; CHECK-NEXT: [[R3:%.*]] = shl i65 1, -18446744073709551615
; CHECK-NEXT: store i65 [[R3]], i65* [[P]]
; CHECK-NEXT: ret void
@ -43,8 +47,10 @@ define void @shift_undef_65(i65* %p) {
define void @shift_undef_256(i256* %p) {
; CHECK-LABEL: @shift_undef_256(
; CHECK-NEXT: store i256 0, i256* [[P:%.*]]
; CHECK-NEXT: store i256 0, i256* [[P]]
; CHECK-NEXT: [[R1:%.*]] = lshr i256 2, 18446744073709551617
; CHECK-NEXT: store i256 [[R1]], i256* [[P:%.*]]
; CHECK-NEXT: [[R2:%.*]] = ashr i256 4, 18446744073709551618
; CHECK-NEXT: store i256 [[R2]], i256* [[P]]
; CHECK-NEXT: [[R3:%.*]] = shl i256 1, 18446744073709551619
; CHECK-NEXT: store i256 [[R3]], i256* [[P]]
; CHECK-NEXT: ret void
@ -63,8 +69,10 @@ define void @shift_undef_256(i256* %p) {
define void @shift_undef_511(i511* %p) {
; CHECK-LABEL: @shift_undef_511(
; CHECK-NEXT: store i511 0, i511* [[P:%.*]]
; CHECK-NEXT: store i511 -1, i511* [[P]]
; CHECK-NEXT: [[R1:%.*]] = lshr i511 -1, 1208925819614629174706276
; CHECK-NEXT: store i511 [[R1]], i511* [[P:%.*]]
; CHECK-NEXT: [[R2:%.*]] = ashr i511 -2, 1208925819614629174706200
; CHECK-NEXT: store i511 [[R2]], i511* [[P]]
; CHECK-NEXT: [[R3:%.*]] = shl i511 -3, 1208925819614629174706180
; CHECK-NEXT: store i511 [[R3]], i511* [[P]]
; CHECK-NEXT: ret void

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@ -2,7 +2,8 @@
target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f80:128:128-n8:16:32-S128"
; CHECK: store volatile <2 x i64> zeroinitializer, <2 x i64>* %p
; FIXME: Add back support for handling special values of vector/fp types.
; CHECK: store volatile <2 x i64> %and.i119.i, <2 x i64>* %p
; rdar://11324230
define void @foo(<2 x i64>* %p) nounwind {